Apparatus for making a closure on a container

ABSTRACT

An apparatus for forming covers of heat shrinkable material on dish-shaped containers comprising means for maintaining a film cover on a container, means for gathering the edge of the film extending beyond the edge of the container into a skirt and heat sealing means adjacent to the support to heat shrink the gathered edge of the film.

U United States Patent [151 3,701,234 Sternau 1 Oct. 31, 1972 [54] APPARATUS FOR MAKING A Primary Examiner-Travis S. McGehee CLOSURE ON A CONTAINER Attorney-John J. Toney, William D. Lee, Jr. and Ed- [72] Inventor: Martln M. Sternau, Flushing, N.Y. ward Hanson r [73] Assignee: W. R. Grace 8: C0,, Duncan, S.C.

[22] Filed: March 12, 1971 [21] Appl. No.: 123,856

Related U.S. Application Data [63] Continuation of Ser. No. 665,419, Sept. 5, 1967, abandoned, which is a continuation of Ser. No. 591,628, June 15, 1956.

[52] US. Cl ..53/329 [51] Int. Cl. ..B65b 7/28 [58] Field of Search ..53/42, 329, 296

[56] References Cited UNITED STATES PATENTS 3,345,798 10/1967 Sternau ..53/42 X [57] ABSTRACT An apparatus for forming covers of heat shrinkable material on dish-shaped containers comprising means for maintaining a film cover on a container, means for gathering the edge of the film extending beyond the edge of the container into a skirt and heat sealing means adjacent to the support to heat shrink the gathered edge of the film.

2 Claims, 18 Drawing Figures P'A TENTEDucm 1972 FIG. 5

FIG. 2

IN VEN TOR. MARTIN M. STE RNAU TTORNEY P'ATENTEDHNBI w 3.101.234

SHEET 3 [If 4 v I /9 FIG. a l d0 INVENTOR. MARTIN M. STERNAU ATTORNEY PATENTEH am a 1 m2 SHEET t [If 4 APPARATUS FOR MAKING A CLOSURE ON A CONTAINER This application is a continuation of Ser. No. 665,419, filed Sept. 5, 1967 now abandoned, which is a continuation of 591,628, filed June 15, 1956.

One of the objects of my invention is to provide a closure which is an inexpensive, simple hermetic seal for a container irrespective of whether the container is made of paper, plastic, aluminum, steel, etc.

Another object of my invention is to provide a hermetic seal for a container irrespective of whether the container is made of paper, plastic, glass, aluminum, steel, etc.

Another object of my invention is to provide a twopart closure comprising an inner sealing closure and an outer protective closure.

Another object of my invention is to provide a closure formed form a transparent oriented plastic sheet alone, or from two dissimilar materials, the inner component being formed of a transparent oriented plastic sheet and the outer component being formed of a semirigid, moldable material.

Another object of my invention is to provide a sealing closure that will permit removal and replacement of the outer cover whereby inspection of the contents of the container may be had without breaking the seal of the inner component, thereby eliminating the danger of contamination.

Another object of my invention is to provide a closure which will enclose the rim of the container in a sanitary manner.

Another object of my invention is to provide a closure which will reduce the cost of manufacture of the container by reducing the amount of container material required.

One of the aspects of this invention is a closure made of flexible and moldable material, and particularly a closure having a beaded and expansible rim.

One of the objects of my invention is to make an improved closure, with or without an inside cover of plastic material, in which the rim is pleated before being formed or rolled in such a manner that expansion and contraction at the rim area may occur to receive and to hold the slightly larger bead on the mouth of a container by locking the rim of the closure below the bead of the container.

Another object ofmy invention is to provide a method and apparatus for forming the cover and for positioning the cover on a container.

Another object of my invention is to provide a method of holding or retaining transparent, oriented plastic sheet material during conversion into a hermetic sealing cover on a container.

Another object of my invention is to provide a method of sealing a plastic sheet closure on a container.

Another object of my invention is to provide a method of manufacturing a hermetically sealing cover from basic raw sheet materials directly upon the container upon which it shall be used and at the time of closure of the container, using the container as the male forming component of the closure.

Another object of my invention is to provide a heat sealing closure for a container.

Another object of my invention is to provide a construction of materials that may be manufactured into a hermetic closure prior to or during application on the container.

A still further object of my invention is to provide a cord to tear open either the plastic film or both covers when a two part closure is used.

A still further object of my invention is to provide additional sealing means in case additional sealing insurance is desirable.

With the foregoing and other objects in view as will appear from a reading of the following specification and claims, the invention resides in the novel arrangement and combination of parts and in the details of construction and process of manufacture hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention may be made within the scope of what is claimed without departing from the spirit of the invention. It will be further understood that the invention is susceptible of embodiment in many and various forms, some of which are illustrated in the accompanying drawing, and that the structural details or particular steps of the method herein set forth may be varied to suit particular purposes and still remain within the inventive concept.

Referring briefly to the figures:

FIG. 1 illustrates a two-ply closure in a vertical sectional view;

FIG. 2 shows a two-ply closure according to the invention ready for use;

FIGS. 3, 4, 5 and 6 show various types of protective covers which shield the inside sealing cover on different type containers;

FIGS. 7 and 7a show another type closure before and after crimping is accomplished;

FIGS. 8 and 8a show a similar type of two-part closure before and after beading same together with container;

FIG. 9 shows a single cover which has an opening string beneath it;

FIG. 10 shows additional sealing cement beneath the sealing cover;

FIG. 11 illustrates a forming apparatus with curling rings, a male die having a resilient ring in it (which may be omitted) to form a peripheral crease or indentation in the sidewall of the closureand a peripheral groove in the female die for providing said indentation;

FIG. 1 la shows a capping and sealing tool for snapping the cover over a receptacle and retaining it while heat is applied to seal the inner cover;

FIG. 12 shows a suction head which carries the shrinkable film and seals it to the receptacle;

FIG. 13 shows a different type apparatus for applying heat to the closure to seal the inner layer after crimp- FIG. 14 illustrates a two-ply closure with an inspection hole in the outer layer;

FIG. 15 illustrates a straight sided container 32 with a modified two-part closure formed from two rolls.

This invention is for a system providing a closure of circular, rectangular, hexagonal, or any other shape for a receptacle. The closure consists of a combination, laminated or otherwise physically held in approximately uniform parallel position, of an inner or underside cover of a shrinkable and clear, translucent, or opaque, film or sheet, and an outer cover of a moldable, rigid or semirigid, and clear, translucent, or opaque material, such as, aluminum, paper, plastic, glass, steel, etc. The inner cover is to provide a seal for the container on which the closure is used, and the outer cover is to pro vide a mold or retaining form or device for the former during the sealing operation and to provide an ultimate protecting cover for the former and for the container upon which this closure is used.

As one example, the outer cover of the closure possesses a peripheral flange formed prior to, or during, the operation affixing the closure cover or covers to the container and having applied at its outer rim or edge means wherein both components of the closure are rolled, curled, bent or otherwise temporarily or permanently held together so that the inner component of the closure is held or retained by or within the rim, of the outer component. The securing together of the two covers or components is done prior to, during, or after the sealing operation. I

There are several possibilities by which a closure as outlined above may be put into apractical form:

1. A closure may be made as shown in FIG. 2 comprising plies of a dissimilar material, the inner layer consisting of a transparent film shrinkable under heat application, the outer layer made of aluminum sheet or any other moldable material. Both components are formed into a cover having, as one example, a circular top portion and an integral peripheral flange and a beaded rim. If this type closure is snapped onto a container with a beaded or a plain edge, the bead of the closure will be locked circumferentially below the rim of the container. When heat is applied selectively to the rim of the closure or the container, the following takes place:

a. The film will shrink a maximum distance circumferentially around the rim of the container with the result that:

b. It willpull the beaded rim of the outer layer of the closure tighter around the circumference below the bead of the container. This occurs because both elements are engaged thereby making the outer cover tighter on the container.

c. The shrunken film will conform to the shape and irregularities of the container rim creating an additional seal around the rim of the container.

d. Due to this local, circumferential shrinkage the remainder of the film under the outer layer will be pulled tightly across-the mouth of the container, still further improving the seal at the mouth of the container.

. Should wax or a heat sensitive cement be applied to the rim of the container before attaching the cover, an additional seal will be formed at the time of heat application.

Similarly, the above function takes place with different type closures used on different type containers.

2. A cover may be made as shown in FIG. 1, for example. This cover has a peripheral crease to facilitate the formation of a peripheral bulge (FIG. 2) before the closure is snapped onto the container. A closure as shown in FIG. 1 has the advantage of economical space saving stacking for packaging.

' 3. A closure may be made using an outer single-ply cover of aluminum, or paper, etc. as a retainer for a shrinkable plastic sheet, which is substantially larger than the mouth of the container. The plastic'sheet is placed on top of the container, and the cover snapped onto the container. This will create the essential condition that the film is held flat across the mouth of the container, while the rim of the film is arranged around the rim of the container in pleats protruding beyond the outer cover. Thus, when heat is applied to the rim, the protruding film will shrink, conforming to the shape of the rim of the container and forming therewith a tight seal around said rim, while the remainder of the film is pulled tightly across the mouth of the container. This third method has the advantage that the outer cover can be removed without disturbing the seal of the film portion of the closure. This process has the additional advantage that the outer cover can be repeatedly taken off and snapped back onto the container without losing its original efiiciency of snapping onto the container, and locking below its rim due to its expandable pleated rim.

4. A closure may be made as shown generally in FIG. 1 or FIG. 2 but with the outer cover 30 having a hole 31 in the center for visual inspection through the transparent inner cover without removing the cover or breaking the seal, all as shown specifically in FIG. 14.

It is not necessary, but if desired, as shown in FIG. 10 wax, cement, etc. 14 may be applied prior to or during the sealing operation at the point of seal upon the container, and said material will adhere to the shrinking or shrunken film during the sealing operation and thereby provide double protection against leakage. Also, ariy of the covers may have incorporated a means of tearing, or otherwise removing said sealed film cover by means of a string, band, etc. 13 by having this device incorporated into the cover construction prior to or during the sealing operation as shown in FIG. 9.

Since the rim of the plastic film portion is rolled into the rim of the aluminum portion of the closure, it is locked and retained by the aluminum portion of the cover. Consequently, when this cover is snapped on an aluminum container, and heat is selectively .and circumferentially applied to the cover, the plastic film portion will shrink a maximum circumferentially around the rim of the container at the point of the application of heat due to its inherent characteristics. Thus it will take the shape and configuration of the rim of the circular, rectangular, or other shape of the container, and create therewith a leakproof seal around the rim of the container.

It is a novel feature to place a sheet of shrinkable, oriented plastic film on top of a paper, plastic or aluminum sheet or foil container to hold it by any outer cover and by subjecting it selectively to heat, to shrink it around the mouth of the closure, thereby forming a leakproof seal.

FIG. 1 shows an outside cover somewhat similar to the .cap illustrated in my previous invention, Ser. No. 289,032, U.S. Pat. No. 2,756,921, granted July 31, 1956, upon which this is, in certain respects, an improvement. Among other things, the invention as illustrated in FIG. 1 is directed to a more or less loose roll or double fold of the rim whereby the pleated area in the rim is freely able to expand and contract as the cover is slipped over the mouth of the container. Also, a thin plastic film cover may be applied, if desired, in connection with the outer cover.

Numeral 1 represents the rigid cover made of flexible, moldable material, such as aluminum, paper or plastic, while 2 indicates the crease formed in the flange of the cover and 3 indicates the more or less loose roll of the rim. Obviously, edge 3 may be formed with a double fold rather than a loose roll, the main consideration being that the edge be expansible and lock beneath the edge of the container. Numeral 4 indicates the pleats which are formed in the flange of the cover and 5, if a liner is used, illustrates such liner or inside cover.

Upon the application of pressure as the cap is being secured to the container, due to the crease, the bulge will be formed, as clearly indicated in FIG. 2.

FIGS. 3 to 6 indicate various types of closures, in which numeral 5 illustrates the inside plastic cover with various types of outside protective covers such as cover 1 in FIG. 3; cover 6 in FIG. 4; cover 7 in FIG. 5, and cover 8 with a central depressed portion in FIG. 6. These covers may be placed on dissimilar type containers 9, 29, etc. Clearly, the two covers may be laid flat over a straight sided container as shown in FIG. 15.

FIGS. 7 and 7a illustrate a plastic film cover 5 and protective cover 10 placed over container 9. subsequently these covers are crimped around to make a tight closure, as illustrated in FIG. 7a, and heat is then applied selectively around the rim.

FIGS. 8 and 8a depict a straight edge container 12 having an inside plastic cover 5 and a recessed closure 11 applied over the top of the inside cover, both before and after the rolling, beading or crimping and heat sealing operation.

FIG. 9 shows the container 9, in which only a onepart closure or transparent plastic cover 5 is applied to the container, and secured thereto is an opening string 13. This type closure is ideally suited,'in a circular container, for bakery goods, such as, cakes and pastries or, in a rectangular package, for food products.

FIG. 10 shows a plastic sheet 5 secured to container 9 with additional sealing cement 14 at various spots, or completely around the edge of the rim. Obviously, the opening means of FIG. 9 could be applied to the closure FIG. 10 or any other figures, with or without the outside cover, and likewise, the sealing cement 14 of FIG. 10 could be applied to the other constructions.

FIGS. 11, 1 la, 12 and 13 illustrate the dies which can be used in making the cover and in sealing the con tainer as set forth in applicants invention.

FIG. 1 1 shows a male die 15 having a resilient ring 16 therein. Female die 17 has a groove 18 opposite the resilient ring 16 in the male die. Upon pressure being applied by the male or forcing die, the closure being formed is forced into the groove by means of the elasticity of the resilient material to form the crease. At the same time, curling rings 19 and 20 form the rim of the cover. The resilient ring 16 may be omitted if desired, but then a less pronounced crease will be formed.

The two-part closure is then picked up by the suction in the capping and sealing tool 21 (FIG. 11a) which has a suction line 22 therein, and as the container 9 is snapped beneath the formed cap, or vice versa, heat is applied to the rim of the closure through apertures 23a. The heat may be applied by hot air, hot water, steam, electricity, or even by an open flame. The application of heat will cause the oriented plastic film to shrink around the rim of the contalnerand therefore form a tight, leakproof seal. Tools 21, 23 are of asbestos, hard rubber, etc., either entirely, or around heat passageways.

FIG. 12 shows a different type of suction sealing disc 23 having suction lines and positioning lines 24 in it.

While FIG. 12 shows only a shrinkable film being placed over the receptacle and sealed by means of hot air or steam passing through apertures 25, it is clear that a two-part closure could be just as easily used.

FIG. 13 shows a different type of crimping and sealing device 26 having hot air apertures 27 therein and a hold-down plate 28.

FIG. 14 illustrates my invention with a different type closure having a body portion 30 with an opening 31 in the center by means of which the contents of the container may be seen through the plastic inner cover 5.

FIG. 15 shows a roll 36 of outer protective material 35, and a roll 34 of inner transparent material 33, both of which are positioned over a straight, non-beaded, circular or rectangular container 32. A shears 37 cuts both layers of the material in cooperation with a heat sealing and crimping device; for example, as shown in FIG. 11a. The shears may be combined with the heat sealing and crimping device if desired so as to provide a one-motion operation for sealing a container from basic sheet material. Similarly, the two components of the closure may be fed from one roll, having been rerolled onto the single roll in a prior operation.

It is therefore clearly apparent that I have invented a sanitary cover which will decrease the quantity of, for example, .aluminum, topack a certain amount of goods. This is true because in the ordinary inside friction closure sealed on an inwardly extending rib from the top, approximately 8 percent of the normal capacity of the container is wasted. With this flexible, transparent film across the very top, the entire container may be utilized. This is particularly so in aluminum packaging which is becoming so common today. Also connected with this sanitary feature is the sales appeal of transparent closures in which the public demands to see that which they are purchasing, especially in the food field.

My invention may be used either as a one-stage or a two-stage operation. In other words, the transparent film may be used alone or the outside cover may be used alone, or if the combination closure is used, the inside cover may be first applied and then the outside cover applied later, or, in a more practical way, the two covers may be formed together and applied as a laminated unitary closure.

It is therefore seen that there has been provided a leakproof and moistureproof closure which is easy to manufacture and is inexpensive. While the invention is particularly adapted for outside covers and containers of aluminum, the invention is equally effective for paper, plastic, steel, etc.

Other modifications of the principal items of this invention are clearly apparent, and I do not desire to be limited in my invention except as set forth in the claims.

I claim:

1. An apparatus for forming a cover of heat shrinkable film material on an open-mouthed container having a peripheral rim about its mouth comprising:

a. means for maintaining said film cover on said container, said means including means for directing the edge of the film which extends beyond the edge of said containers mouth into a downwardly depending skirt; and,

b. means integral with means (a) for directing a stream of heated gas downwardly and inwardly to urge said skirt against said container below its rim 

1. An apparatus for forming a cover of heat shrinkable film material on an open-mouthed container having a peripheral rim about its mouth comprising: a. means for maintaining said film cover on said container, said means including means for directing the edge of the film which extends beyond the edge of said container''s mouth into a downwardly depending skirt; and, b. means integral with means (a) for directing a stream of heated gas downwardly and inwardly to urge said skirt against said container below its rim and thereby shrink said skirt, said means being located above the lower edge of said depending skirt.
 2. The apparatus of claim 1 wherein means (b) comprises peripherally distributed apertures which direct said gas downwardly and inwardly against the lower edge of said skirt. 